Abstract: A new method for controlling movement of a digging dipper includes providing an earthmoving machine with two drive systems for moving the dipper along two respective paths. Also provided is a control apparatus having a reference axis and a knob mounted for movement between a first, repose position and a maximum position spaced from the repose position by a maximum displacement dimension. The knob is displaced along a control axis to a second position which is spaced from the repose position by an actual displacement dimension less than the maximum displacement dimension. The drive systems are energized and the dipper is powered along a digging axis generally parallel to the control axis. A new apparatus for controlling movement of the dipper has a single control knob having a repose position and also has first and second motion transducers mechanically coupled to the knob.

Abstract: Disclosed is a clevis of the type used with a digging bucket. The clevis is of the type having a pivot pin and a pin locking assembly. In the improvement, the pivot pin is cylindrical, has first and second opposing ends and at least one hole traversing the pin diameter. A first boss is affixed on the clevis around the first end and such boss has a plurality of key slots formed therein. A retaining ring is seated in each of the key slots and a first retaining pin extends through the hole and the retaining rings. Most preferably, the clevis has another boss at the pivot pin second end and another retaining pin extends through the pivot pin second end. A new method is also disclosed.

Abstract: Disclosed is a digging implement such as a mining shovel dipper which has a body, a movable door mounted with respect to the body and a mechanism for retarding swinging movement of the door. The mechanism includes first and second housings and plural retarding discs compressed between the housings. In the improvement, a resilient member is interposed between the first housing and the discs. And most preferably, a separate resilient member is interposed between each housing, respectively, and the discs. The thickness of each resilient member is selected in view of the aggregate thickness of the discs and the number of resilient members if more than one such member is used. A highly preferred resilient member is an elastomeric washer. The new retarding mechanism substantially extends the time period between mechanism adjustments and results in improved machine productivity.

Abstract: An overhead crane adapted to be supported on a pair of spaced apart, generally parallel first and second rails, the crane having a frame having opposite first and second ends, a first wheel rotatably mounted on the first end of the frame, the first wheel being adapted to roll along the first rail, a second wheel rotatably mounted on the second end of the frame, the second wheel being adapted to roll along the second rail, a first bearing assembly supporting the first wheel, a second bearing assembly supporting the second wheel, each of the first and second bearing assemblies including a bearing supporting the associated wheel for rotation relative to the frame about a rotation axis, the rotation axis having a position relative to the frame, and a mechanism connecting the bearing to the frame and allowing the bearing to be fixed in various positions relative to the frame, a hoist supported by the frame, and a load engaging mechanism which is raised and lowered by the hoist.

Abstract: A material-handling machine includes a substantially horizontal girder having an end, a supporting flanged wheel at the end, a truck having rail-riding wheels on a rail and a girder mid-portion extending from the end and connected to a support leg extending between the mid-portion and the truck. The leg and the mid-portion are connected by a pin permitting relative movement between the mid-portion and the leg. Such pinned connection reduces wear of the rail and the rail-riding wheels and reduces bending stress in the support leg.

Abstract: A draglined bucket having first and second contoured dumping rails respectively supported on first and second spaced apart opposite sidewalls and a rear wall. Each dumping rail extends from above the sidewall on which it is supported to the rear wall on which it is also supported. Rollers are connected to a hoist rope and support the bucket in a suspended manner. The rollers engage the first and second dumping rails and are movable along the dumping rails from a forward position in which an open end of the bucket faces substantially horizontally, to a rearward position in which the open end of the bucket faces downwardly to dump material in it. The dumping rails adjacent to the rear wall of the bucket are preferably spaced from the rear wall of the bucket. The rollers include first and second rollers which respectively engage the undersides of the first and second dumping rails.

Abstract: An anode positioning hoist supported on an overhead crane used in a smelting apparatus including a cathode with an upwardly facing surface and an anode with a downwardly facing surface. The anode positioning hoist includes a pair of channel members defining opposed vertical channels and a cylinder/piston assembly including a cylinder located between the channel members and a piston rod extending downwardly from the cylinder. A carrier is fixed to the piston rod for movement therewith and includes rollers guided in the channels. A connector assembly is mounted on the carrier to releasably secure the anode to the carrier. A control system including a counterbalance valve mounted on the cylinder and a pressure switch operates to cause extension of the piston rod until the downwardly facing surface of the anode engages the upwardly facing surface of the cathode. The control system thereafter causes retraction of the piston rod a predetermined distance to provide a desired anode-cathode gap.

Abstract: Disclosed is a polar crane supported by a rail and having a bridge and a bridge-supporting end truck at each end of the bridge. Each end truck has, for either direction of revolving bridge motion, a leading wheel contacting the rail. In the improvement, the leading wheel of each end truck has a single flange and the flange is inward of the rail. Skewed crane "lock-up" is thereby substantially prevented. A related method for modifying a polar crane includes raising the first end truck away from the rail, removing a two-flange wheel (the leading wheel) from the first end truck and installing a one-flange wheel in place thereof.

Abstract: Apparatus comprising a lower support structure having an upper surface, a circular lower rail which is mounted on the upper surface of the lower support structure and which is centered on a generally vertical axis, an upper structure having a lower surface, a circular upper rail which is mounted on the lower surface of the upper structure and which is centered on the axis, a plurality of rollers which are located between the upper and lower rails and which support the upper structure for rotation relative to the lower structure about the axis, the rollers being rotatable about respective generally horizontal axes intersecting the vertical axis at a common point, one of the rails including an inwardly facing surface defining a portion of a sphere centered on the point, and each of the rollers including an outwardly facing surface which engages the inwardly facing surface and which defines a portion of a sphere centered on the point.

Abstract: A load lifting apparatus comprising: a frame; a load engaging mechanism for engaging a load having a weight; a hoist mechanism for raising the load engaging mechanism, the hoist mechanism being mounted on the frame and including a member supporting the load engaging mechanism during lifting of the load, the member having therein an aperture; a sensor disposed in the aperture for detecting a force exerted by the load engaging mechanism on the member, the sensor providing a variable output indicative of the magnitude of the force; and a control for disabling the hoist mechanism when the output reaches a first predetermined value corresponding to the maximum load of the load lifting apparatus.

Abstract: A rigging assembly for a dragline bucket has first and second hoist chains coupled to the bucket and first and second pickup links above the hoist chains. The chains extend along first and second axes, respectively, and define a fleet angle between them. In the improvement, the pickup links define a link angle between them which is substantially equal to the fleet angle. The pickup links are coupled with respect to respective hoist sockets by pins, the hoist chains are coupled with respect to the pickup links by other pins and all of the pins have substantially equal cross-sectional areas. Most preferably, the pins are identical to one another for parts "commonality.

Abstract: An automatic breakout wrench with: the clamping jaw located on the inside of the pipe so that the clamping grip is not reduced by the force of the breakout cylinder; the orientation of the breakout cylinder resulting in the breakout cylinder creating a moment that forces the wrench toward the pipe rather than away from the pipe; pivotal movement of the wrench member guided by three pins; the wrench member pivoting twenty-four degrees; the clamping jaw pivotally mounted on one of the pins guiding movement of the wrench member; and shims secured in a manner so as to be easily inserted and removed.

Abstract: Heavy machinery comprising a lower support structure having an upper surface, and an upper structure having a generally horizontal lower surface facing the upper surface of the lower structure, the upper structure being supported above the lower structure for rotation relative to the lower structure about a generally vertical axis, and the lower surface of the upper structure having therein an upwardly extending recess surrounding the axis to provide space for a person working on the machinery, the recess being defined at least in part by an upper wall above and generally parallel to the lower surface, and by a plurality of generally planar facets surrounding the axis, each of the facets extending transversely to the upper wall and to the lower surface.

Abstract: A dragline comprising a main housing, a bucket hoist mechanism mounted on the housing, a bucket drag mechanism mounted on the main housing, a moving mechanism for moving the main housing over the ground, a boom which is supported on the main housing and which has an upper end, a bucket, a hoist rope having one end connected to the bucket hoist mechanism, extending over the sheave, and having an opposite end, a drag rope extending between the bucket and the bucket drag mechanism, a dump block including a frame having a main portion connected to the opposite end of the hoist rope, and a cantilevered spindle extending from the main portion, and a dump block sheave mounted on the spindle for rotation about a sheave axis, and a dump rope extending over the dump block sheave and having one end connected to the drag rope and an opposite end connected to the bucket, such that the dump rope can be removed from the sheave in the direction away from the frame main portion.

Abstract: A dragline comprising a main housing, a bucket hoist mechanism mounted on the housing, a bucket drag mechanism mounted on the main housing, a moving mechanism for moving the main housing over the ground, a boom having upper and lower ends and a rectangular cross-section, the lower end being connected to the main housing, the upper end having thereon a sheave, the boom having a longitudinal axis and including a center section having top and bottom members parallel to the longitudinal axis, the center section having a neutral axis above the longitudinal axis, structure supporting the boom relative to the main housing, a bucket, a hoist rope extending between the bucket and the bucket hoist mechanism and over the sheave for causing vertical movement of the bucket, and a drag rope extending between the bucket and the bucket drag mechanism for causing horizontal movement of the bucket.

Abstract: A system having two or more A.C. motors driving the same load. The stator windings and rotors of both motors each conduct current having a vector representative of a magnitude and angular position of the current in the respective rotor and stator winding. Stator current sensors are provided for producing an indication of the magnitude of the stator current vector to each motor. Encoders are provided for sensing the rotating speed of each of the rotors from which can be calculated the angular position of the rotor load current vector with respect to the rotating stator flux current vector. A first torque control controls the magnitude of the stator current of a first one of the motors such that the stator flux current vector of the first motor and the rotor load current vector of the first motor are angularly separated by 90.degree.. This angular relationship produces maximum torque at the rotating speed of the first motor.

Abstract: A blasthole drill comprising a frame supported for movement over the ground, a mast supported by the frame for movement relative thereto between a substantially vertical position and a non-vertical position, the mast defining a drill hole axis, a drill-through pipe rack mounted on the mast, the pipe rack including a rack member, a gate mounted on the rack member, the gate having open and closed modes and being adapted to support the lower end of a drill pipe when the gate is in the closed mode, the gate permitting the drill pipe to move downwardly relative to the gate when the gate switches to the open mode, and the gate allowing movement of the rack member away from a drill pipe previously supported by the gate when the gate is in the open mode, a mechanism for moving the rack member horizontally relative to the mast and between an extended position wherein a drill pipe supported by the gate is on the drill hole axis and a retracted position wherein the gate is spaced from a drill pipe on the drill hole axis

Abstract: Disclosed is a digging implement (such as a dragline bucket) having a trunnion link connected to the implement by a pin secured in place by a retention device. Such device is coupled to the pin along the pin longitudinal axis. The pin has a first portion engaging the implement and having internal threads and the retention device has a stop member and an exteriorly-threaded stem extending therefrom. The stem is threaded to the internal threads of the first portion. Preferably, the stop member is recessed in a protective pocket which helps protect the retention device from damage otherwise caused by material being handled by the implement.

Abstract: A dragline comprising a main housing, a bucket hoist mechanism mounted on the housing, a bucket drag mechanism mounted on the main housing, a walking mechanism for moving the main housing over the ground, the walking mechanism including a motor mounted on the main housing, a planetary transmission which is mounted on the main housing and which is driven by the motor, a transmission output shaft driven by the transmission, a walk leg housing connected to the output shaft via an output pinion, a driven gear, and a driven eccentric such that rotation of the output shaft causes walking movement of the walk leg housing, and a shoe fixed to the walk leg housing for engaging the ground during walking movement of the walk leg housing, a boom extending from the main housing, a bucket, a hoist rope extending between the bucket and the bucket hoist mechanism and over the sheave for causing vertical movement of the bucket, and a drag rope extending between the bucket and the bucket drag mechanism for causing horizontal m

Abstract: The disclosure involves a crane having a main hoist drum and an auxiliary hoist drum for handling a load under normal and emergency (the latter actual or simulated) conditions, respectively. The latter condition involves a main hoist which is inoperative because of a failure or by intent. The auxiliary hoist drum is wrapped with about twice the length of cable as the main drum and can move the load up or down, irrespective of load position if and when the main hoist becomes inoperative. Also disclosed is a novel method for moving a load. Steps include maintaining one drum in a non-rotating mode and rotating the other drum. An improved crane load block is also disclosed to have "floating sheaves" which help prevent excessive fleet angles.